Surveycr&#39;s compass



Nov. 28, 1933. F. LEUPOLD sURvEYoR'S COMPASS Filed Dec. 20, 1932 La@ www? QN ww QP. mi' I.N\ s NI www mi N mM Patented Nov. 28, 1933 SURVEYORS COMPASS f YFrederick Leupold, Portland, Oreg., assignor to Leupold, Volpel fand y Company,

Oreg.

Portland,

Application December 20, 1932 Serial No. 648,059 Y 4 elaine. (ores- 69) My invention relates to surveyors Compasses in which the levelingv tubes and other necessary or important parts areinclo'sed in a 'water-tight box; in which the l,rim of the enclosing ring is lower thanthe surface of the cover-glass; in

which horizontal cross-wires are stationarily attached to the front sight; and in which graduated scales are removably attached to there'ar sight.

The objects of my invention are to manufacture a surveyors compass which can conveniently be carried in a coat pocket; which cannot collect water on the covering glass, which prevents water from entering the inside oi the compass box; which protects the leveling tubes, the graduated circle, and the index, from the influx of water or from tampering, or accidental damage; which permits adjustment of the graduated circle for magnetic variations; and which permits the reading of horizontal, as well as vertical angles. Other objects and advantages are to be ound in the construction and arrangement of parts as will be described in the specication and particularly pointed out in theappended claims.

I attain these objects with the mechanism illustrated in the accompanying drawing, in which; Fig. 1 is a plan view o the entire apparatus.

Fig. 2 is a side view of Fig. 1.

Fig. 8 is an elevation of the rear sight.

Fig. 4 is an elevation of the iront sight.

Fig. 5 is an elevation of the index bracket in the compass box.

Fig. 6 is a section through Fig. 5 along the line Similar numerals refer to similar parts throughout the several views.

My compass consists of a box l, with an ear 2 for the front sight, and an ear 8 for the rear sight, integrally attached thereto. A straight edge Il at one side o the box 1, and parallel to the ears 2 and 3, may be used for measuring or for drawing. The two leveling tubes 5-5 are placed in the bottom of the box 1, where they are protected from breakage or tampering. The magnetic needle 6 is poised in the center of the box 1 and is provided with the customary needle-lifter 7. The housing 8 at the outside of the compass box 1, which is entered by the short armof the needlelifter '7, and which is provided with theA lifting screw 9, is cast integrally with the compass box l, so that no opening cr crevice is leftwhereby water may enter. In the outer circumference of the box 1 is turned an annular seat 10 for the reception of a ring 11, which latter rotates with a water-tight it in the seat li). Radially directed guide screws 12, in the ring l1, enter an annular groove 13 in the seat 10 and prevent accidental removal of the ring 11,'without irnpeding rotation of the latter. VThe inner wall surface of the ring 11, above the compass box 1, has an annular shoulder 14'to the bottom of which is securely alixed a graduated circle 15, designatingY thevcardinal points. A relatively heavy glass cover 1`6 is let into the Iring 1l `on top ofthe annular rshoulder 14,and attached with water-proof cement. The'upper surface of the glass cover 16 should be higher than the rim of the ring 11, so that no rain water can accumulate on top of the glass cover 16. An index bracket 17, Figs. 5 and 6, irmly secured to the bottom td., of the compass box 1, carries an index 18 in thev precise line of sight, and readable in conjunction with the graduated circle 15, to adjust the latter for magnetic variations of the needle 6.

Hingedly attached to the front ear 2 of the 75s compass box 1 is the front sight 19 with the customary vertical cross-wire 20. A loop 21, at one side of the front sight 19, and near the bottom thereof, carries a horizontal cross-wire 22. A similar loop 23, at the other side of the front sight SQA 19, and near the top thereof, carries the horizontal cross-wire 24.

Also hingedly attached, but to the rear ear 3 of the Vcompass box 1, isthe rear sight 25, with the customary vertical slit 26. On one side of 8.5., v

the slit 26, and held to the rear sight 25 by means of the screws 27, is a graduated scale 28, whose zero point is level with the horizontal cross-wire 22-on the front sight 19. Minus readings are taken toward the top of this scale 28. On the 31dA other side of the slit 26, and held in place by the screws 29, is a similar graduatedrscale 30, whose zero point, however, is level with the horizontal cross-wire 24 on the front sight 19, from which zero point plus readings are taken toward the 9,5, bottom. The scales 28 and 30 may be graduated in degrees or percentages of slope to suit the convenience of the operator, and, by removal of the screws 27 and 29, an exchange of scales may be easily effected.l

It is, of course, to be understood that the graduations lon the scales 28 and 30 must be accurately proportioned to the distance between the two sights 19 and 25.

The two sights 19 and 25, when not in use, mai7 1.0.5 be folded in as indicated by the dotted lines inV Fig. 2.

In operation this apparatus is mounted on a tripod or Jacobs stair, as indicated by the numeral 31 in Fig. 2, the two sights are raised, the gradu- 1,1 0

struction, I reserve to myself the right to make.

minor changes providing I do not contravene the spirit and principle of my invention.

I claim:

1. In a surveyors compass,the combination of Ya compass box, a ring closely fitting and rotatably mounted on the box, a graduated circle, having cardinal points, rmly secured in the ring, a glass cover cemented in the ring above the graduated circle whereby to form a closed casing, the upper surface of the glass being higher than the rim of the encircling rim, leveling tubes on the bottom of the box, an index on the bottom of the box readable in conjunction with the gradu ated circle to adjust said graduated circle for magnetic variations, with means foldably attached to the compass box to measure horizontal and vertical angles.

j 2. In a surveyors compass, the combination of acompass box, a front ear integrally attached to the compass box,v a rear ear integrally attached to the diametrically opposite side of the compass box, a housing cast integrally with the outer circumference of the compass box, a lifting screw mounted in the housing, a needle-lifter entering the housing from the inside of the compass box and terminating under the lifting screw, a straight edge at one side of the compass box and parallel with the ears, With means foldably attached to the ears to measure horizontal and vertical angles.

3. In a surveyors compass, the combination of a Water-tight compass, a front sight hingedly attached to the compass, a rear sight hingedly at- Y tached to the compass, horizontal cross-Wires extending from each side of the front sight, and graduated scales removably attached to the sides of the rear sight,` said graduated scales, in conjunction with the horizontal cross-wires, indicating vertical angles.

4. In a surveyors compass, the combination of a water-tight compass, a front sight hingedly attached to the compass, a rear sight hingedly attached to the compass, a. bottom loop attached to one side of the front sighta horizontal crosswire in said bottom loop, a. top loop at the opposite side of the front sight, a horizontal crossf Tf wire in said top loop, a graduated scale removably attached to each side of the rear sight, the zero point on each graduated scale being level with the corresponding horizontal cross-Wire on the front sight.

FREDERICK LEUPOLD. 

